• 2014 - A Survey and Classification of Controlled Natural Languages

• Cramer et al 2009 - The Naproche Project Controlled Natural Language Proof Checking of Mathematical Texts

From Diller 2019:

Attempto Controlled English (ACE) (Fuchs et al., 2008) is a prominent controlled natural language (CNL) for knowledge representation (KR). Apart of its appropriateness for basic KR, ACE’s attraction comes, first of all, from its ties with formal logic: ACE texts have an unambiguous translation to first order logic (FOL). Secondly, there are several open-source tools for ACE; the main one being the parser APE, which translates ACE texts to FOL via discourse representation structures (DRSs) (Blackburn and Bos, 2005) and also verbalises DRSs.

Main site: Attempto Project. See also Wikipedia - Attempto Controlled English. For more papers see Attempto Publications.

• Fuchs et al 2008 - Attempto Controlled English for Knowledge Representation
• Diller et al 2019 - Making sense of conflicting (defeasible) rules in the controlled natural language ACE: design of a system with support for existential quantification using skolemization